1. Field of the Invention
The present invention relates to a method for manufacturing an electronic component and an apparatus for manufacturing the same, particularly to a method for manufacturing an electronic component that requires a paste such as a conductive paste to be coated on a part of the side faces of a component body provided with an electronic component, and to an apparatus for manufacturing the same.
2. Description of the Related Art
FIG. 16 shows a perspective view of the appearance of an electronic component 1 in concern with the present invention. The electronic component having three or more terminals such as, for example, a three-terminal capacitor, a capacitor array, a LC composite EMI filter and a capacitor network assumes an appearance as shown in FIG. 16.
The electronic component 1 comprises, for example, a rectangular column shaped electronic part 2. The terminals provided on this electronic component 1 include end face electrodes 5 and 6 formed on the end faces 3 and 4, respectively, in opposed relation with each other, while side face electrodes 9 and 10 are formed with a predetermined width on the other side faces 7 and 8, respectively, in opposed relation with each other.
Not only the end face electrodes 5 and 6 are formed on the end faces 3 and 4, respectively, but also adjoining face extension parts 13 and 14 are extended onto a part of the side faces 7 and 8 adjoining the end faces 3 and 4, besides extending up to a part of the other pair of the side faces 11 and 12. The side face electrodes 9 and 10 not only extend onto the side faces 7 and 8, respectively, but also have adjoining face extension parts 15 and 16 extending up to a part of the side faces 11 and 12 adjoining the side face electrodes 9 and 10.
These adjoining face extension parts 13 to 16 serve for improving soldering property to the wiring board (not shown) when the electronic part 1 is mounted thereon.
What is concerned with the present invention is a technology particularly for forming the side face electrodes 9 and 10.
An apparatus 17 is shown in FIG. 17 in order to form the side face electrodes 9 and 10. The apparatus 17 is provided with a slit plate 18 made of a metal, and a plurality of slits 19 having a width corresponding to the width of the side face electrodes 9 and 10 are provided on the slit plate 18. The slit plate 18 is placed so as to shut the upper opening of a paste vessel 21 accommodating a conductive paste 20. A cylinder 22 is provided to be connected with the space in the paste vessel 21, and a piston is provided in the cylinder 22.
The component body 2 is firstly disposed so that its one side face 7 contacts the slit plate 18. The conductive paste 20 is fed through the slit 19 by allowing the piston 23 to move along the direction of an arrow 24 so that the paste swells on the upper face of the slit plate 18, while the side face of the component body is in contact with the slit plate, thereby the conductive paste 20 is coated on a part of the side face 7 of the component body 2. The conductive paste is also coated on a part of the side faces 11 and 12 adjoining the side face 7 of the component body 2.
The same procedure is also applied to the other side face 8 of the component body 2.
Subsequently, the conductive paste 20 coated on the component body 2 is baked, and the side face electrodes 9 and 10 comprising the adjoining face extension parts 15 and 16, respectively, as shown in FIG. 16 are formed using the conductive paste 20.
An apparatus 25 is also shown in FIG. 18 in place of the foregoing apparatus 17.
The apparatus 25 has a coating plate 26 comprising an elastic material capable of elastic deformation such as a rubber. A plurality of grooves 27 having a width corresponding to the width of the side face electrode 9 or 10 are provided on the coating plate 26, and the grooves 27 are filled with the conductive paste 28.
The component body 2 is compressed against the coating plate 26 while one side face 7 comes into contact with the coating plate 26, thereby the component body 2 allows the coating plate 26 to deform along the direction of thickness. As a result, the conductive paste 28 in the groove 27 is coated on a part of the side face 7 of the component body 2 with a predetermined width, as well as on a part of the adjoining side faces 11 and 12 by allowing a part of the conductive paste 28 to swell onto the upper face of the coating plate 26.
The same step is also applied on the other side face 8 of the component body 2.
The conductive paste 28 is baked thereafter by the same way as in the case using the apparatus 17 shown in FIG. 17. The side face electrodes 9 and 10 having the adjoining face extension parts 15 and 16 as shown in FIG. 16 are formed using the conductive paste 28.
However, the following problems arise when the apparatus 17 shown in FIG. 17 is used.
As hitherto described, a plurality of slits 19 are provided on the slit plate 18, and the component bodies 2 corresponding to respective slits 19 are disposed. The plural component bodies 2 are held by being arranged on a plane using an appropriate holder (not shown), and are positioned so as to correspond to respective slits 19.
However, it happens that some of the components bodies 2 may be accidentally deficient at specified portions of the holder, when a plurality of the components bodies 2 are held with the holder, whereby no component bodies 2 are present on the specified portions of the slit 19 remaining the portion of the slit to be open. Consequently, since the pressure applied from the piston 23 is readily released through the open portion of the slit 19, the amount of the coated conductive paste 20 on the component body 2, particularly the coating level of the conductive paste 20 to serve as the adjoining face elongation parts 15 and 16, tends to be irregular. This irregularity may well arise not only among the component bodies 2 that are simultaneously treated, but also among the component bodies 2 that are treated in each repeating process.
For solving the problems as described above, it is contemplated to coat the conductive paste 20 on the component body 2 after forming a gap between the component body 2 and the slit plate 18. However, it is difficult to form the side face electrode 9 or 10 with a uniform width, because the width of the side face electrode 9 or 10 becomes wider to an extent not to be negligible than the width of the slit 19, besides making the width of the electrodes wider at the center of the side face. Accordingly, such solving means are inappropriate when the side face electrode 9 or 10 should be formed with finer width, or when a plurality of the side face electrodes having a narrow pitch are desired to be formed on specified side faces (not shown).
For solving the foregoing problems, it can be also contemplated that the slit 19 is so designed as to have a narrower width than the width required for the side face electrode 9 or 10. However, the conductive paste 20 turns out to be left in the slit thus requiring the slit as well as the paste vessel 21 to be frequently cleaned, arising a problem of decreased work efficiency.
The following problems arise, on the other hand, when the apparatus 25 as shown in FIG. 18 is used.
The elastic material such as a rubber constituting the coating plate 26 may be swelled by the effect of organic solvents contained in the conductive paste 28. The organic solvents are pervaded into the elastic material with time lapsing. Such swelling and pervasion not only shortens the service life of the coating plate 26, but also accidentally happens to deform the coating plate 26, thereby the positional accuracy for coating the conductive paste 28 onto the component body 2 is decreased with time.
Frequent cleaning of the coating plate 26 is also required, since the conductive paste is liable to be remained in the groove 27 because the conductive paste 28 filled in the groove 27 of the coating plate 26 is dried up, or the organic solvent contained in the conductive paste infiltrates into the coating plate 26, also arising a problem that the work efficiency is decreased.
Accordingly, the object of the present invention is to provide a method for manufacturing an electronic component and an apparatus for manufacturing the same that can simultaneously solve the problems that are encountered in the conventional art.
The present invention according to the present invention is directed toward a method for manufacturing an electronic component comprising the steps of preparing a component body, and applying a paste on a part of side faces of the component body with a predetermined width, and comprising the construction as will be described below for solving the technical problems as hitherto described.
The method for manufacturing an electronic component according to the present invention comprises the steps of: preparing a slit plate on which slits having a width corresponding to the width for applying the paste are provided, the slit having a first and second principal face in opposed relation with each other with a predetermined distance apart and the first principal face side serving as a side for disposing the component body; a shutter member comprising an elastic material disposed so as to shut the opening of the slit at the second principal face side of the slit plate; and a compression member for compressing the shutter member so as to allow the shutter member to undergo elastic deformation toward the inside of the slit.
The paste is then filled in the slit, and the component body is disposed so that the side face of the component body is directed toward the first principal face side of the slit plate.
Subsequently, the shutter member is allowed to undergo elastic deformation toward the inside of the slit by compressing the shutter member with the compression member, thereby applying the paste on the part of the side face of the component body while supplying the paste filled in the slit so as to swell onto the first principal face side.
Preferably, the slit plate comprises a plurality of slits. The component body is disposed on the first principal face side by disposing a plurality of the component bodies so as to correspond to each of the plural slits, thereby the paste can be applied on one site on the side face of the component body. Otherwise, the paste can be applied on plural sites on the side face of the component body by disposing one of the component bodies so as to be laid across the plural slits.
The first principal face side of the slit plate is preferably allowed to be in contact with the side face of the component body, when the component body is disposed on the first principal face of the slit plate in the method for manufacturing an electronic component according to the present invention.
The paste in the slit may be applied on the component body so that, not only the paste is applied on a part of the side face of the component body, but also the paste extends from a part of the side face of the component body onto a part of the adjoining face in the method for manufacturing an electronic component according to the present invention.
It is preferable that the step for filling the paste into the slit comprises a step for supplying the paste from the first principal face side of the slit plate into the slit in the method for manufacturing an electronic component according to the present invention.
More preferably, the shutter member is allowed to undergo elastic deformation toward the inside of the slit by compressing the shutter member with the compression member in advance, followed by restoring elastic deformation of the shutter member by releasing the pressure applied to the shutter member from the compression member after applying the paste so as to cover the slit on the first principal face side, thereby to suck the paste into the slit.
More preferably, the step for applying the paste so as to cover the slit on the first principal face side comprises applying the paste so as to extend onto the first principal face, additionally comprising the step of raking the excess paste on the first principal face followed by squeezing the paste into the slit by allowing a squeezer to operate on the first principal face after the step for sucking the paste into the slit.
Preferably, a conductive paste for forming electrodes on a part of the side faces of the component body is used for the paste in the method for manufacturing an electronic component according to the present invention.
The present invention is also directed toward an apparatus for manufacturing an electronic component on which a paste is applied on a part of side faces of a component body with a predetermined width.
The apparatus comprises a slit plate on which slits to be filled with the paste and having a width corresponding to the width for applying the paste are provided, the slit plate having a first and second principal face in opposed relation with each other with a predetermined distance apart, and the first principal face side serving as a side for disposing the component body.
The apparatus also provided with a shutter member comprising an elastic member disposed so as to shut the opening of the slit on the second principal face of the slit plate.
The apparatus further comprises a compression member for compressing the shutter member so as to allow the shutter member to undergo elastic deformation toward the inside of the slit, in order to apply the paste in the slit on a part of the side face of the component body while supplying the paste filled in the slit so as to swell on the first principal face side.
It is preferable that a plurality of the slits are provided on the slit plate in the apparatus for forming an electronic component according to the present invention.
In providing a plurality of the slits, spaces in the slit are preferably defined so that they are not connected with each other among the component bodies to be applied with the paste the plural slits, when the plural slits are provided for applying the paste on the component body.
Preferably, the compression member is provided with projections arranged at the sites in opposed relation to the slits in the apparatus for forming an electronic component according to the present invention. Each projection of the compression member may be provided so as to correspond to each one of the slits, or each projection thereof may be provided so as to correspond to or cover the plural slits, when a plurality of the slits are provided on the slit plate.
Preferably, a cavity being wider than the slit to define a space connected with the space in the slit is provided on at least one of the second principal face side of the slit plate and the slit plate side of the shutter member in the apparatus for manufacturing an electronic component according to the present invention.
When the cavities are provided as described above besides providing a plurality of the slits on the slit plate, each cavity may be provided so as to correspond to each one of slits, or each cavity may be provided so as to correspond to or cover the plural slits.